The invention relates to ink jet printers and in particular to methods for assembling ink jet pen components of multi-color pens using thin film adhesives.
Ink jet printers are continually undergoing design changes to improve the speed and print quality produced by such printers in order to provide printed images which have the appearance of laser printed media. One important advantage of ink jet printers over that of laser printers is that multi-color images may be produced relatively less expensively than with laser printers. Multicolor images are produced by depositing dots of different colors in precise patterns on the print media. One of the difficulties associated with multicolor printing is that the printheads of the individual ink jet pens used to produce the images must be aligned with each other so that the dot placement errors or minimized. Exact alignment of all critical printhead components during the assembly of an ink jet pen is extremely difficult to achieve. Even if the parts are initially aligned, it is difficult to maintain the alignment throughout the manufacturing process without the use of costly jigs. Even with elaborate alignment equipment, because of the size of the parts, extremely small alignment errors may have a major impact on the performance of the pens in a printer.
The manufacture of a multi-color ink jet is typically a multi-step process. The most common multicolor printer uses individual ink jet pens for each color of ink. The components of the pens including the printheads are aligned and assembled with respect to their pen bodies. The individual pens are then attached to a carriage in side by side relationship. Once the pens are attached to the carriage, the pens may be individually adjusted to provide the desired alignment between the different pen colors. The components of each of the pens are aligned with respect to reference marks on the pen bodies and alignment between the individual color pens is conducted after all of the components of the pens are assembled and attached to the carriage. A disadvantage of this method for aligning the ink jet pens is that multiple alignment steps are required for the individual pens and there is a possibility that misalignment may occur due to wear or damage thereby requiring another costly alignment step.
It is difficult to produce multicolor pens having two or more printheads attached to the same ink jet pen body because of the need to maintain alignment of the pen components. Thin film adhesives have attributes that make them desirable for use in the assembly of ink jet pens. For example, thin film adhesives are available that have substantially uniform thickness. However, such adhesives also have numerous attributes that render them difficult to handle or otherwise work with and thus the use of such adhesives are problematic in a production setting. There is a need therefore for manufacturing techniques and apparatus that facilitate the use of thin film adhesives in the manufacture of ink jet pens.
With regard to the foregoing, the invention provides a method for attaching microelectronic devices, circuit boards and the like to a surface, and is particularly suitable for attaching a plurality of semiconductor chips to an ink jet pen body. The method includes the steps of (a) providing a sheet of a thin film adhesive material having a first surface and a second surface opposite the first surface, the second surface being releasably attached to a carrier web; (b) simultaneously making a plurality of cuts in the sheet of thin film adhesive material, the cuts extending from the first surface to an interface between the second surface and the carrier web without significantly extending into the carrier web to provide one or more cut portions of adhesive film; (c) removing each cut portion of adhesive film from the carrier web; (d) engaging the second surface of each of the cut portions with predetermined locations on a receiving surface; (e) providing one or more semiconductor chips in a desirably aligned configuration with respect to the predetermined locations and contacting each semiconductor chip with first surface of each of the cut portions; and (f) curing the thin film adhesive in order to substantially bond the chips to the receiving surface.
In another aspect, the invention relates to apparatus for simultaneously cutting two or more strips of thin film adhesive and thereafter simultaneously applying the plurality of strips of thin film adhesive to a component of an ink jet pen in the manufacture of the ink jet pen.
In a preferred embodiment, the apparatus includes a plurality of cutting/application assemblies desirably aligned with one another and spaced apart from one another a predetermined distance corresponding to desired application positions of the strips of thin film adhesive to an ink jet pen. A plurality of shafts capable of reciprocating movement relative to the cutting/application assemblies are provided, one each operatively associated with one of the cutting/application assemblies. A control assembly is provided for controlling movement of the shafts and for movably positioning the cutting/application assemblies relative to a workpiece such as a sheet of adhesive or an ink jet pen component. A plurality of rigid connecting members are provided for connecting each cutting/application member to the control assembly.
Each of the cutting/application assemblies includes a stamping die having a perimeter defining a surface thereof of suitable configuration for cutting portions of thin film adhesive of a predetermined configuration from a sheet of thin film adhesive. An insert is movably positionable within a portion of the stamping die adjacent to the perimeter and has a surface suitable for receiving a cut portion of the thin film adhesive. Each of the shafts is operatively associated with one of the inserts and the control assembly.
The invention advantageously facilitates the handling of thin film adhesives in the manufacture of microelectronic devices, such as ink jet pens. The invention provides conveniences in the cutting and application of thin film adhesives so that precisely cut portions of film material may be cut and accurately placed without undue handling thereof and without subjecting the film material to handling procedures that promote damage to the materials.